Partially unroofed coronary sinus: MDCT and MRI findings

The purpose of this study was to analyze the MDCT and MRI findings in patients with unroofed coronary sinus syndrome.

This retrospective study included 11 patients with unroofed coronary sinus syndrome (10 adults, one child) without persistent left superior vena cava and one adult with communication of the left atrium and coronary sinus via an anomalous vein (unroofed coronary sinus variant). Four patients underwent contrast-enhanced ECG-gated MDCT; six, MRI; and two patients, both CT and MRI. We also measured the coronary sinus on the CT scans of 28 adults with normal cardiac anatomy and 10 adults with persistent left superior vena cava and compared the measurements with those in the patients with unroofed coronary sinus syndrome. Seven patients underwent surgical treatment of unroofed coronary sinus syndrome.

At echocardiography, unroofed coronary sinus syndrome was not clearly discriminated from atrial septal defect in two patients and was not suspected in three patients. CT and MRI showed that 11 patients had a defect in which the coronary sinus communicated with the left atrium and that the other patient had atresia of the coronary sinus orifice with an anomalous vein connecting the coronary sinus and left atrium. In patients with unroofed coronary sinus syndrome, the mean standardized diameter of the coronary sinus according to the patient's body surface area was 15 ± 4 mm/m², similar to that of the control group with persistent left superior vena cava (15 ± 6 mm/m²; p = 0.97) and significantly greater than that of the group with normal cardiac anatomy (7 ± 2 mm/m²; p < 0.0001).

CT and MRI facilitate definite diagnosis of unroofed coronary sinus syndrome.